Taurine: An Osmolyte in Mammalian Tissues

Abstract

One of the distinctive features of taurine is its presence at high levels in most animal tissues5,3. Although differences exist among cells and species, taurine is consistently found in mM concentrations. It is noteworthy that excitable tissues including brain, striatal muscle and heart contain large, inert, and intracellular taurine pools3,9. The most prominent example in this respect is the retina. In all species so far examined, retinal taurine levels exceed 20 mM and in some species its concentration is as high as 60 mM39. In addition to these high levels, taurine in excitable tissues has a very slow turnover rate. In rat organs, values for taurine turnover rate fit into three main groups: those with a relatively fast rate calculated in less than 1 day and include liver, kidney and pancreas; a second group, with a medium rate of about 2–3 days comprises lung, spleen, intestine, testes, bone marrow and the third group, with the slowest rate of more than 3 days and up to 7 days, is represented by brain, heart and muscle30;.